Device for use in tearing sheet material



y 9 H. w. PUS i-IECK 2,349,635

DEVICE FOR USE IN TEARING SHEET MATERIAL Filed Feb. 27, 1945 fi F Wm INVENTOR. WrWPw/ww Patente d May 23, 1944 DEVICE FOR USE IN TEARING SHEET MATERIAL Herbert W. I'usheck, Evanston, lill.

Application February 27, 1943, Serial No. M7368 5 Claims.

The object of this invention is to provide an improved device for use in tearing corrugated paper, which device supports a long strip of corrugated paper in roll form, enables a section of the strip of any desired length to be pulled from the roll and torn off evenly, and holds the new end of the strip in an easily accessible position in readiness for the next pulling and tearing operation.

Although the device is primarily designed for use in tearing corrugated paper, and-is of particularly great value in that connection because of the diiiiculties ordinarily experienced in tearing corrugated paper, it should be understood that the device is also applicable to other kinds of tearable material, such as paper generally, Cellophane, and the like.

While the foregoing statements are indicative in a general way of the nature of the invention, other more specific objects and advantages will be apparent to those skilled in the art upon a full understanding of the construction and operation of the device.

One embodiment of the invention is presented herein by way of exemplification, but it will of course be appreciated that the invention is sus" ceptible of incorporation in other structurally modified forms coming equally within the scope of the appended claims.

In the accompanying drawing:

Fig. l is a perspective view of a device constructed in accordance with the invention;

Fig. 2 is a vertical section through the center of the device;

Fig. 3 is a horizontal section, taken on the line 3-3 of Fig. 2; and

Fig. l is a fragmentary vertical section, taken on the line Q4 of Fig. 3, showing in more detail the stationary tear-off bar and the movable holding bar.

The device shown in the drawing comprises a stand in which is adapted to be screwed or otherwise rigidly secured to a wrapping counter or other flat working surface. The stand is characterized by two upright side frames H of generally triangular form. The side frames are connected together at the back of the stand by a horizontal brace I2, and are connected together at the front of the stand. by a horizontal tear-off bar it. The side frai .es provided at their upper ends with upwardly opening notches i i for removably supporting the ends of a rod If on which a roll iii of corrugated paper is adapted to be rotatably mounted. The side frames are preferably spaced i apart just far enough to clear the ends of the roll.

The roll it is composed of a long strip l'lof corrugated paper. The strip ll preferably consists of a plain sheet I8 and a corrugated sheet l9. The corrugated sheet If! is bonded to the plain sheet l8 with the corrugations 20 in the sheet I9 running crosswise of the strip, thus rendering the strip laterally stifi but longitudinally flexible.

From the roll it the strip l1 extends downwardly at the back of the stand to a guide rod 2|, and then extends forwardly beneath the guide rod to the previously mentioned tear-off bar I3. The bar I3 is preferably arranged at an inclination of about 415, and its forwardly inclined under surface 22 is preferably covered by a thin sheet metal plate 23, which plate terminates just forwardly of the front edge of the bar in a sharp edge 2i which provides an effective tearing blade.

The strip [1 contacts the metal-sheathed surface 22 of the bar It intermediate the front and rear edges of the latter, and is pressed into engagement with the surface 22 by a horizontal holding bar 25, which bar is positioned immediately behind the bar I3 in parallel relation to the latter. The bar 25 is arranged with its upper surface in rearwardly diverging relation to the inclined under surface of the bar 13 and is provided along its front edge with a rounded cam-like nose portion 26 which is disposed in rearwardly wedging engagement with the under surface of the strip ll throughout the width of the latter. The bar 25 is pivoted near its front edge to the side frames l l by pins Zll for tilting movement, and is provided with rearwardly extending counterweight members 28 which tend to press the nose portion 26 upwardly against the inclined under surface of the strip l1.

It will be observed that the nose portion 2% of the bar 25 extends forwardly from the pivotal axis of the bar into engagement with the strip I! at an acute angle to the plane of the latter, which angle is preferably somewhere in the neighborhood of 45 but may be somewhat larger or smaller. This acute angular arrangement allows the strip H to be pulled forwardly without appreciable resistance, but prevents it from moving backwardly and keeps it at all times snugly pressed against the under surface of the bar IS in readiness to be torn crosswise when pulled forwardly the desired distance. When the strip is being torn crosswise the clamping pressure exerted against the same by the nose portion 25 will prevent the strip from moving sidewise while the Wedging action exerted will at the same time prevent the strip from moving backwardly, thus securely holding the strip to permit it to be torn off easily and cleanly.

After a section of the strip I! has been torn off a new edge 29 will of course be left on the front end of the strip. This new edge 29 will assume a downwardly curved more or less pendent position beneath the correspondingly curved nose portion 26 at a point just back of and below the blade 24, Where it can be easily grasped.

While the tear-off bar l3 has been shown in an inclined position and the holding bar 25 in a substantially horizontal position, it will of course be appreciated that such positions can be reversed without affectin the operation of the device.

I claim:

1. In a device of the character described, a stationary tear-off bar against which a strip of tearable sheet material is adapted to be pressed, and a pivotally mounted holding bar for pressing the strip of sheet material against the tear-01f bar at a point rearwardly of the front edge of the latter, said holding bar being biased toward the tear-off bar and being provided along its front edge with a nose portion which extends forwardly from the pivotal axis of the bar into engagement with the strip at an acute angle to the plane of the latter.

2. In a device of the character described, a stationary tear-off bar against the under surface of which a strip of tearable sheet material is adapted to be pressed, said tear-off bar being provided near its front edge with a blade having a sharp tearing extremity, which extremity is engaged by the strip onl while the latter is being torn, and a pivotally mounted holdin bar for pressing the strip of sheet material against the under surface of the tear-off bar at a point rearwardly of the tearing extremity of the blade, said holding bar being biased toward the tearoif bar and being provided along its front edge with a nose-portion which extends forwardly from the pivotal axis of the bar into engagement with the strip at an acute angle to the plane f the latter.

3. In a device of the character described, a stationary wooden tear-off bar against the under surface of which a strip of corrugated paper is adapted to be pressed, said tear-off bar being provided near its front edge with a sheet metal blade having a sharp tearin extremity, which extremit i engaged by the corrugated paper only while the latter is being torn, and a pivotally mounted holding bar for pressing the strip of corrugated paper against the under surface of the tear-off bar at a point rearwardly of the tearing extremity of the blade, said holding bar being biased toward the tear-off bar and being provided along its front edge with a nose portion which extends forwardly from the pivotal axis of the bar into engagement with the strip at an acute angle to the plane of the latter.

4. In a device of the character described, a stationary tear-off bar against the under surface of which a strip of corrugated paper is adapted to be pressed, said tear-off bar being provided near its front edge with a sharp tearin blade, and a pivotally mounted holding bar for pressing the strip of corrugated paper against the under surface of the tear-off bar at a point intermediate the front and rear edges of the latter, said holding bar being biased toward the tear-off bar and being provided along its front edge with a rounded cam-like nose portion which extends forwardly from the pivotal axis of the bar into engagement with the strip at an angle of about 45 to the plane of the latter.

5. In a device of the character described, a stationary member against the underside of which a strip of tearable sheet material is adapted to be pressed, a pivotally mounted holding member for engaging the underside of the strip and pressing it against the stationary member, and a stationary blade having a sharp tearing edge against the underside of which the strip is adapted to be positioned when the latter is being torn, said pivotally mounted holding member being biased toward the stationary member and being provided along its front edge with a nose portion which extends forwardly from the pivotal axis thereof into engagement with the strip at an acute angle to the plane of the latter, the point of engagement of said pivotally mounted member with the strip being spaced rearwardly a substantial distance from the point of engagement of said tearing edge with the strip, whereby to leave the strip after each tearing operation with its front edge unconfined.

HERBERT W. PUSHECK. 

